How is Chronic Myelomonocytic Leukemia Diagnosed?

Medically Reviewed by: Dr. Douglas Tremblay

Chronic myelomonocytic leukemia (CMML) is diagnosed through a series of tests that examine the blood and bone marrow. The process usually begins with a physical examination, during which the doctor checks for physical signs of CMML, such as fatigue, weight loss, frequent infections, pale skin, and liver and spleen enlargement. 

If CMML is suspected, the following tests may be conducted:

Blood Tests

• Complete blood count (CBC): This test measures the amount of different types of cells in the blood. In CMML, there may be an increase in the number of monocytes, a type of white blood cell, and a decrease in other types of blood cells, such as red blood cells and platelets.
• Peripheral blood smear: In this test, a sample of the patient's blood is examined under a microscope to check for abnormal cells. 
• Lactate dehydrogenase (LDH): LDH is an enzyme released from damaged or rapidly dividing cells. Elevated LDH levels may be observed in the blood of cancer patients.
  
• Erythrocyte sedimentation rate (ESR): An increased ESR may indicate inflammation or infection.

Bone Marrow Tests

• Bone marrow aspiration and biopsy: These tests involve taking a small amount of bone marrow from the hipbone or breastbone and examining it under a microscope. The presence of increased monocytes in the bone marrow is a characteristic finding in CMML.
• Flow cytometry: This test is used to measure the number of cells in a sample of bone marrow, as well as their size, shape, and the presence of certain markers on the cell surface. It can help diagnose CMML.
• Cytogenetic Analysis: This test may reveal specific genetic abnormalities, including chromosomal rearrangements or mutations. The presence of certain genetic markers, such as the presence of the Philadelphia chromosome (Ph), can also provide diagnostic information.
• Next-Generation Sequencing (NGS): Is a test uses an advanced technique that can sequence an entire human genome in a single day. It is used to identify gene mutations in CMML cells.

Imaging Tests

• Computed Tomography (CT) scan: A CT scan can provide detailed images of the inside of the body. It is usually done to assess spleen size. 

A Summary of Diagnosing Chronic Myelomonocytic Leukemia

It's important to note that the diagnosis and classification of CMML are complex and require a comprehensive evaluation by a team of specialists. If you don't currently have a CMML specialist on your care team, it is important that you consult with one to get an accurate diagnosis. Use HealthTree's CMML Specialist Directory to locate a specialist near you. 

The specific markers and genetic changes found in a bone marrow sample can offer important information about a person's prognosis, helping to predict how CMML will progress. This information is also useful in making treatment decisions. Click here to learn more about the prognosis for CMML and what to expect regarding life expectancy for those affected by this condition.

What Are The Signs and Symptoms of CMML?